It was in 1907 when Korea was annexed by Japan in the field of health care systems as the Gwangje Hospital, Uihakgyo the National Medical School and the Korean Red Cross Hospital were merged into the colonial Daehan Hospital, and massive cholera epidemic controls by the Japanese Army were enforced. However, despite their importance, the cholera epidemic of 1907 in Korea and preventive measures taken at that time have not yet been studied extensively as a single research subject. The purpose of this paper is to contribute to a more concrete and broader understanding of the Korea-Japan annexation of health care systems under the rule of the Japanese Resident-General of Korea by revealing new facts and correcting existing errors. In 1907, cholera was transmitted to Korea from China and Japan and spread across the Korean Peninsula, resulting in a major public health crisis, perhaps one of the most serious cholera outbreaks in the twentieth century Korea. Although Busan and Pyeongyang were the cities most infected with cholera, the targets for the most intensive interventions were Gyeongseong (Seoul) and Incheon, where the Japanese Crown Prince were supposed to make a visit. The Japanese police commissioner took several anti-cholera preventive measures in Gyeongseong, including searching out patients, disinfecting and blocking infected areas, and isolating the confirmed or suspected. Nevertheless, cholera was about to be rampant especially among Japanese residents. In this situation, Itō Hirobumi, the first Resident-General of Korea, organized the temporary cholera control headquarters to push ahead the visit of the Japanese Crown Prince for his political purposes to colonize Korea. To dispel Emperor Meiji's concerns, Itō had to appoint Satō Susumu, the famous Japanese Army Surgeon General, as an advisor, since he had much credit at Court. In addition, as the Japanese-led Korean police lacked epidemic control ability and experience, the headquarters became an improvised organization commanded by the Japanese Army in Korea and wielded great influence on the formation of the colonial disease control systems. Its activities were forced, violent, and negligent, and many Korean people were quite uncooperative in some anti-cholera measures. As a result, the Japanese Army in Korea took the initiative away from the Korean police in epidemic controls, serving the heavy-handed military policy of early colonial period. In short, the cholera epidemic and its control in 1907 were important events that shaped the direction of Japan's colonial rule.